代 is like the generation. One generation is 一代。 輩 is similar, but it is used with word that represents seniority. The senior is 長輩， the junior is 後輩
What is the difference between 代 (dài) and 輩 (bèi)?
代 is like the generation. One generation is 一代。 輩 is similar, but it is used with word that represents seniority. The senior is 長輩， the junior is 後輩